Explanation

Question: A girl throws a small stone into a lake. Waves spread out from where the stone hits the water and travel to the bank of the lake. She notices that ten waves reach the side of the pond in a time of 5.0s. What is the frequency of the waves?

Answer: Frequency is defined as the number of waves (or cycles) per second. In this case, 10 waves reach the bank in 5 seconds, so:

Frequency = Number of waves / Time

= 10 waves / 5 s

= 2 waves/s

= 2.0 Hz